Tree Ferns

How to choose a tree fern

The Fern Tree is Cyathea cooperi, the lacy tree fern from Queensland and New South Wales. It is the fastest of the group, with a slim trunk marked by neat oval scars and fronds that can pass three metres long. In gardens it commonly reaches four to six metres, and it accepts more sun than most ferns once its roots are kept moist.

The Rough Tree Fern is Cyathea australis, slower and tougher, with a thicker trunk covered in the rough bases of old fronds. It is the better choice for cooler districts, taking frost and more exposure than the lacy tree fern.

For small spaces there are two compact options. The Little Aussie Larrikin Dwarf Norfolk Island Tree Fern is a dwarf selection of a species that is very tall in the wild. The Volcano Dwarf Brazilian Tree Fern is a different plant again: a water fern that builds a short trunk over time and is grown for the reddish colour of its new fronds.

Where tree ferns grow

Give them the conditions of a gully: dappled light or morning sun, shelter from hot afternoon sun and drying wind, and soil that stays evenly moist. The south or east side of a house, a courtyard or the space under tall trees all suit. Wind is the main enemy, as it shreds and browns the fronds. The lacy tree fern suits subtropical and warm temperate gardens and needs frost protection while young. The rough tree fern is the one for Melbourne, Canberra and the ranges.

Underplant with smaller ferns and foliage from our ferns for shady areas, birds nest ferns and plants for full shade.

Planting and spacing

Dig plenty of compost into the planting area and set the fern at the level it grew in the pot. Allow for the spread of the crown, which is usually wider than people expect: three to four metres between full sized tree ferns gives each its own umbrella. Mulch thickly with leaf litter or bark.

Care basics

Water the crown and trunk, not just the soil. The trunk is a mass of fibrous roots, and a tree fern takes up much of its water there, so hose it from the top down in warm or windy weather. Feed in spring and summer with a diluted liquid fertiliser. Cut old fronds off close to the trunk once they have browned. The fine hairs on the frond stalks of Cyathea can irritate skin, so wear gloves and long sleeves when pruning. See our tree fern care guide for more.

Common questions

How fast do tree ferns grow?

The lacy tree fern is quick in good conditions and can add 30 centimetres or more of trunk in a year. The rough tree fern is noticeably slower.

Can tree ferns grow in full sun?

The lacy and rough tree ferns will take a good deal of sun in humid, mild climates if the trunk and roots never dry out. In hot, dry or windy positions they scorch, so shade from midday onwards is safer.

Can I grow a tree fern in a pot?

Yes, for some years. Use a large, heavy pot with quality potting mix, keep it out of the wind and never let it dry out. The dwarf forms are the easiest to keep in a container long term.

Why are the fronds on my tree fern turning brown?

Usually dryness, hot sun or wind. Water the crown and trunk more often and check the shelter.